Aprilaire 8353 warranty Features, Replacing Existing Thermostat

Features

•Four setpoints for weekday programming—two setpoints for weekend comfort.

•Two “AA” ENERGIZER brand batteries retain program memory, even during power outages.

•Low battery indicator.

•Fahrenheit/Celsius display option.

•Programmable from 45°F (4°C) to 90°F (32°C).

•Accuracy within ± 1 degree.

•Adjustable temperature differential: 1-3 degrees.

•Maintains summer and winter programming.

•Low temperature freeze protection. While in heat mode, thermostat will mechanically turn on heat if temperature drops to 40°F (4°C) – even if batteries are missing or drained.

•Automatic heating shutdown if temperature exceeds 90°F (32°C).

Replacing Existing Thermostat

1.Turn off power to heating and cooling system.

2.Remove cover of old thermostat to expose wires. Do not disconnect wires. (Fig. 1)

3.Label wires per Table 1.

Table 1

Old Label	New Label	Description
M, 4, RH, R5 or R	RH	Heat Transformer,
		hot side
V or RC	RC	Cooling Transformer, hot
		side
Y or Y6	Y	Cooling control
H, W or 4	W	Heating control
F or G	G	Fan control relay
C*	Y or None	Either cooling control or
		common side of trans-
		former

*NOTE: On some older models, the C terminal can be either the cooling- control or the common side of the transformer. Check furnace wiring diagram to verify C terminal. If it is the common side of the transformer, cap the wire and tuck into the wall. If it is the cooling control, connect to the Y terminal.

4.After labeling wires, remove wires from terminals.

5.Remove existing thermostat base from wall.

6.Refer to the following section for instructions on how to install thermostat.

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